Ias there a way to do this anymore? I can't find how you do it - has it been taken away or am I going mad?

You need to go into your own profile drop-down, to 'Ignored Users' and then you can choose to add a new member to your list from there!

Is there really no way of completely ignoring someone in full? I mean that it's clear when you're ignoring someone as their posts are hidden but then if someone quotes the person you're ignoring you see the post being quoted. It kind of defeats the point of ignoring someone, is there any way around this?

It's as though we need a "Quotes" option on this screen.

I expect that's not so easy given the quote just becomes a part of someone else's post. It's certainly not a feature that exists at the moment anyway unfortunately.